Relationship between HPV and rectal cancer

Dear OncoLink "Ask The Experts," What can you tell me about the relationship between HPV and rectal cancer?

Timothy C. Hoops, MD, Clinical Assistant Professor of Medicine in the Gastroenterology Division at the University of Pennsylvania and Director of Gastroenterology at Penn Medicine at Radnor, responds:

HPV infection is more related to cancers of the anal region then rectum. Squamous cell cancers usually arise from the area around the anus and anal canal. There are several risk factors for these cancers. HPV is a risk factor and patients with anal warts, caused by this virus, should be treated and watched for any changes suggesting the development of cancer. Any chronic inflammatory condition also increases the risk for anal cancer. This includes Crohn's disease, an inflammatory disease of the GI tract. This is particularly true if the inflammation affects the anus, especially if there are fistulas. The same can be said for chronic inflammation such as from fistulas that are not associated with Crohn's. The risk is not very high, but is higher than those without these conditions. Also, patients with HIV are more at risk for developing anal cancers then the general population. In fact, patients that present with anal cancer should undergo testing for HIV.